There are a number of devices on the market for creating bonding and grounding paths between multiple structures because for certain structures, such as suspended cable ladders, it is important to provide an electrical connection or bond between the sections of the structure. This is particularly important in situations where a structure includes multiple sections, and where grounding each section separately would not be feasible.
For example, many electrical mounting assemblies such as cable ladders or conduits, are large and consist of multiple sections for ease of transport and assembly. In order to maintain safety, electrical grounding and bonding between those sections is generally required. Because many mounting devices have a protective paint coating, the direct attachment of sections using conventional nuts and bolts is not, in some cases, sufficient to provide a low-impedance electrical connection. As such, in order to provide adequate grounding, separate grounding wires are typically used to provide electrical continuity, providing a continuous and reliable path for electrical ground faults, high frequency leakage currents, and electrically bonding multiple structures together to form an extension of the “ground plane.” One end of the grounding wire is attached to a first section of the assembly and the other end is attached to an adjacent section. In order to ensure a stable electrical connection, the protective coating (e.g., paint) of the mounting device is removed around the location of the grounding wire attachment. While this type of attachment is generally adequate for providing electrical grounding, the attachment of the grounding wires is time consuming and subject to error should the ground connection not be properly completed.
A product that was recently introduced by Panduit Corporation is referred to as the Tapped Rail Bonding Stud Kit and includes a nut and bolt arrangement with serrations or teeth formed integral to and on the bottom of the nut and bolt. That product is described in detail in U.S. Patent Publication No. 2006/0257229.
While the Panduit product does address the problem for breaking through the paint layer to reach the base metal, Applicant has determined that the product negatively impacts the appearance of the components and can create a corrosion source since the serrations are designed to remove a complete circular ring of paint exposing the bare metal. The ring of bare metal is susceptible to corrosion unless an anti-oxidant is applied. However, application of anti-oxidants is an additional assembly step and can be difficult to apply or in some cases not done at all.